1. Field of the Invention
The present invention relates to an optical disk apparatus for recording data transferred from a host computer on an optical disk, reproducing the data from the optical disk, and transferring the data to the host computer.
2. Description of the Related Art
Optical disk apparatuses have data buffer memories for temporarily storing the data which has been transferred from a host computer and which is to be recorded on an optical disk, and for temporarily storing the data reproduced from the optical data. The conventional optical disk apparatuses have so-called "double buffer-memory structure," and comprise at least two data buffer memories. During a period of time, the first data buffer memories is used for transferring data between the apparatus and the host computer, whereas the second data buffer memory is used for transferring data between the apparatus and the optical disk. During the next period of time, the first buffer memories is used for transferring data between the apparatus and the optical disk, whereas the second data buffer memory is used for transferring data between the apparatus and the host computer.
A conventional optical disk apparatus needs to have two data buffer memories at the least. The data buffer memories are relatively large and expensive. Here arise two problems. First, the apparatus must have a circuit board large enough to hold the data buffer memories, along with the other electronic components. Second, the use of two or more data buffer memories would results in a high manufacturing cost of the apparatus.
At present it is increasingly demanded that an optical disk apparatus be made smaller and be manufactured at lower cost. In view of this it is not advisable to use many data buffer memories which are large and expensive components.